The present invention relates to receivers for, for example, a ship or an aircraft, for receiving signals from navigation satellites such as for example NAVSTAR satellites which form part of a global positioning system.
NAVSTAR is a system which requires a receiver capable of receiving signals simultaneously from at least four NAVSTAR satellites to obtain a navigational fix. The satellites transmit highly stable time-based, spread spectrum signals and navigational data which are received by users. The user's receiver correlates spread spectrum signals from four or more satellites with known spectrum spreading codes to thereby obtain navigational data which is then computed to give the user's position, (see "Navigation", 25, (2), Summer 1978).